Long-Term Outcomes of S-1 Combined With Low-Dose Docetaxel as Neoadjuvant Chemotherapy (N-1 Study, Phase II Trial) in Patients With Operable Breast Cancer.

BACKGROUND: We previously reported that S-1 and low-dose docetaxel (DOC) (N-1 study, phase II trial) could be a well-tolerated and effective neoadjuvant chemotherapies (NACs) for patients with operable breast cancer. Herein, we analyzed the long-term outcomes and developed clinicopathological and molecular predictors of pathological complete response (pCR). PATIENTS AND METHODS: Eighty-three patients received S-1 (40 mg/m2 orally on days 1-14) and DOC (40 mg/m2 intravenously on day 1) every 3 weeks for 4 to 8 cycles. Disease-free survival (DFS) and overall survival (OS) were analyzed for each population with a pCR status. To assess the relationship between pCR and clinicopathological factors such as tumor-infiltrating lymphocytes (TILs, 1+ <10%, 2+ 10%-50%, and 3+ >50%) and nuclear grade (NG), microarray was used to compare the microRNA profiles of the pCR and non-pCR groups using core needle biopsy specimens. RESULTS: With a median follow-up duration of 99.0 (range, 9.0-129.0) months, the 5-year DFS and OS rates were 80.7% and 90.9%, respectively. The 5-year OS rate of the pCR group was significantly better than that of the non-pCR group (100% vs. 86.2%, p = .0176). Specifically, in triple-negative patients, the difference was significant (100% vs. 60.0%, p = .0224). Multivariate analysis revealed that high TILs (≥2-3+) and NG 2-3 independently predicted pCR. Microarray data revealed that 3 miRNAs (miR-215-5p, miR-196a-5p, and miR-196b-5p) were significantly upregulated in the pCR group. CONCLUSION: Our NAC regimen achieved favorable long-term outcomes and significantly improved OS in the pCR group. High TILs, NG 2-3, and some miRNAs may be predictors of pCR.

Absolute Lymphocyte Count Changes During Neoadjuvant Chemotherapy are Associated With Prognosis of Human Epidermal Growth Factor Receptor 2-Positive Breast Cancer Patients.

NTRODUCTION/BACKGROUND: Some reports have shown that absolute lymphocyte count (ALC) is associated with prognosis in breast cancer; however, the impact of ALC changes remains unclear. This study aimed to investigate the relationship between ALC changes during neoadjuvant chemotherapy for human epidermal growth factor receptor-2 (HER2)-positive breast cancer patients and disease prognosis. PATIENTS AND METHODS: This retrospective cohort study January 2010 to September 2020) included patients diagnosed with HER2-positive breast cancer and treated with trastuzumab-based neoadjuvant chemotherapy. The ALC ratio was defined as the ALC value after administration of the anti-HER2 drug divided by the ALC value before administration. The optimal ALC ratio cut-off value was identified using the receiver operating characteristic curve analysis and Youden's index. The relationship between the ALC ratio and disease-free survival was assessed using the Kaplan-Meier method. Univariate and multivariate analyses were performed using the Cox proportional hazards model. RESULTS: Data from a total of 100 HER2-positive breast cancer patients were analyzed. The cut-off value of the ALC ratio was set as 1.142. The median follow-up period was 52.0 (range: 5.1-123.7) months. The 5-year disease-free survival rates were 88.4% and 60.9% in the high-and low-ALC ratio groups, respectively, and were significantly higher in the high-ALC ratio group (p = .0031). The ALC ratio was an independent prognostic factor in multivariate Cox proportional hazards analysis (p = .0032). CONCLUSION: HER2-positive breast cancer patients with a higher ALC ratio during trastuzumab-based neoadjuvant chemotherapy may have a better prognosis than their counterparts.

Phase II Study of S-1 Combined With Low-Dose Docetaxel as Neoadjuvant Chemotherapy for Operable Breast Cancer Patients (N-1 Study).

BACKGROUND: To improve the pathological complete response (pCR) rate, we devised new neoadjuvant chemotherapy. Efficacy and safety of the oral fluoropyrimidine derivative S-1 (Taiho Pharmaceutical Co, Tokyo, Japan) combined with low-dose docetaxel (S-1+DOC) were evaluated. PATIENTS AND METHODS: Patients were treated with docetaxel (40 mg/m2 intravenously on day 1) and S-1 (40 mg/m2 orally twice per day on days 1-14) every 3 weeks for 4 cycles. In accord with the Response Evaluation Criteria In Solid Tumors version 1.1 criteria, the patients who showed a complete response (CR) underwent surgery, and those who achieved a partial response (PR) underwent 4 more cycles of S-1+DOC. Patients who achieved stable disease (SD) or progressive disease (PD) received EC (epirubicin and cyclophosphamide) or HT (trastuzumab and paclitaxel) according to their HER2 status. The primary end point was the pCR rate. RESULTS: Ninety-four patients entered the study. After 4 cycles of S-1+DOC, CR was noted in 5 patients, PR in 57, SD in 18, and PD in 3. Of the patients who achieved SD and PD, 12 received EC, and 9 received HT. Among the 83 assessable patients, the pCR rate was 34.9%, and the response rate was 80.7%. The pCR rates were 19.5% in the luminal type group, 53.8% in the luminal HER2 group, 46.1% in the HER2 group, and 50.0% in the triple-negative group. CONCLUSION: The S-1+DOC regimen in this study could be well tolerated and a new candidate neoadjuvant chemotherapy in operable breast cancer patients. It is also expected to be effective even in patients with luminal type disease. However, further randomized control trials are needed to ascertain whether pCR can contribute to favorable outcomes.